The present invention relates to an apparatus for automatically charging scrap into a steel-making arc furnace.
As shown in FIG. 1, when conventionally scrap a is to be charged into an arc furnace b, a scrap bucket d is moved by a large overhead scrap-charging crane c to the position right above the arc furnace b. In this case, the view of a crane operator e is very limited due to dusty air, smoke and so on above and around the arc furnace b; but in response to a signal transmitted from an operator g on a floor f, the crane operator e must accomplish the fine alignment between the bucket d and the arc furnace b and the fine level adjustment of the bucket d with respect to the arc furnace b. Thereafter the scrap a is charged into the arc furnace b.
However, the prior art method described above has some problems.
(i) In response to the signals transmitted from the floor operator e, the crane operator g must inch the bucket d so that the bucket d is aligned with the arc furnace b. As a result, a long time is required for charging the scrap a into the arc furnace b. That is, the tap-to-tap time is increased so that high productivity cannot be attained. In addition, a furnace roof (not shown in FIG. 1) must be opened for a long time so that a large quantity of heat escapes from the furnace b into the surrounding atmosphere. That is, heat loss is high.
(ii) When the bucket d and the arc furnace b are not correctly aligned with each other, part of the scrap a to be charged falls out of the arc furnace b or the scrap a is accumulated around the top end h of the arc furnace b. As a result, the floor operator g must manually charge the spilled scrap a' and the accumulated scrap a" into the arc furnace b. Therefore a long time is required before the furnace roof is closed and the electrodes (not shown) are powered on. That is, the tap-to-tap time is increased as is the case in (i) so that the high productivity cannot be attained.
The present invention was made to overcome the above and other problems encountered in the prior art system for charging scrap into an arc furnace and has for its object to provide an apparatus for automatically charging scrap into an arc furnace within a short time without overflowing scrap and without accumulating scrap on the top end of the arc furnace so that labor saving and energy saving can be attained and the productivity can be improved.